SCHEDULE II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Doubtful Accounts
Balance at Beginning of Period	$ 1,354	$ 1,525	$ 1,952
Charged to (Reduction of) Costs and Expenses	437	189	(275)
Taken Against Allowance	(100)	(360)	(152)
Other (Deductions) Recoveries	0	0	0
Balance at End of Period	1,691	1,354	1,525
Valuation on Allowance for Deferred Tax Assets
Balance at Beginning of Period	16,889	8,754	6,388
Charged to (Reduction of) Costs and Expenses	656	8,135	2,366
Taken Against Allowance	(2,920)	0	0
Other (Deductions) Recoveries	0	0	0
Balance at End of Period	$ 14,625	$ 16,889	$ 8,754